shoulder &pectoral regions,. objectives identify the bony components of the shoulder girdle...
TRANSCRIPT
Shoulder & Pectoral Regions,
Muscles OF
Objectives
• Identify the bony components of the shoulder girdle including the clavicle, scapula and humerus
• Describe how primary muscles are responsible for the following shoulder motion: adduction, abduction, flexion, extension
Surface Anatomy
Surface Anatomy
Bony Skeleton
• Axial?• Appendicular
• Can you name some?
• Shoulder Girdle..
Bony Skeleton
Shoulder Girdle
AnteriorScapula.-angles, borders-glenoid cavity, -acromion, -coracoid process, -Subscapular fossa
Humerus.-Head,-Surgical neck-Anatomical neck-Greater tubercle-Lesser tubercle-Intertubercular (bicipital) groove
PosteriorClavicle.Acromioclavicular joint
Scapula.- Spine - Acromion- Supraspinous fossa- Infraspinous fossa
Humerus. - Head - Anatomical neck, - Surgical neck, - Deltoid tuberosity- Spiral (radial) groove.
Pectoral Girdle
• Direct : Clavicle , scapula from the trunk Pectoralis minor, trapezius, rhomboids… Most will be discussed in the scapular region lecture
• Indirect : muscles of the great axillary folds as Pectoralis Major, and Latismus dorsi
Movements of the shoulder joint (Scapulohumeral):
Abduction / adductionFlexion / extension
Rotation – internal (medial)- external (lateral)
Movements of the scapula (Thoracoappendicular):(increase range of movement of upper limb)Protraction / RetractionElevation / DepressionRotation: Superior / Inferior
Circumduction
Name the action
We need MUSCLES for all that!!
Muscles are named by either their attachments “Sternohyoid” , location ”Pectoralis”, action “levator”, shape ”quadratus”,direction of fibers “rectus”
Will make our life easier memorizing all the names..Nerve supply of the muscles tells us the story about it’s embryological origin..please pay attention in the embryology classes and enjoy the
integration
Clavicular
Sternocostal
Pectoralis Major: 2 parts- Together (adduction, medial rotation)- Clavicular head (flexion)- Sternocostal head (extension)- (common insertion: lateral lip of intertubercular groove)
Pectoralis minor - deep to pec. major - protraction of scapula - guide to axilla
Poland Syndrome
CongenitalAbsence of Pectoralis MajorPartial or complete absence
Trapezius: 3 parts-Superior fibres elevate (insert lateral 1/3 of clavicle)
-Middle fibres retract (insert acromion)
-Inferior fibres depress (insert spine of scapula)
- Acting together, thesuperior and inferiorfibres will rotate scapula.
Superior
Middle
Inferior
Latissimus Dorsi:-(inserts floor of intertubercular groove)
-Extends, adducts and medially rotates humerus.
Butterfly swimming, CrutchClimbing a tree
Anterior
Deltoid: 3 parts-Anterior (flexion, med. rotation)-Middle (abduction)-Posterior (extension, lat. rotation)-(common insertion: deltoid tuberosity)
Posterior
Posterior view:- Trapezius- Latissimus Dorsi- Deltoid
Rhomboids:- minor and major- retract / inferior rotate scapula
Teres major:- inserts near latissimus dorsi- adduct / medially rotate arm
Anterior Arm.– Biceps brachi– Coracobrachialis
Actions: Biceps – supination + flexion (shoulder, elbow)Coracobrachialis – weak flexion / adduction (shoulder)
Shoulder Flexion
Posterior Arm.-Triceps (3 heads)-long head extends shoulder.
Action: Extension
Shoulder Extension
Adduction – pectoralis major, lattisimus dorsi.Abduction – deltoid, supraspinatus.Flexion – pectoralis major, deltoid (anterior),
– coracobrachialis, biceps.Extension – latissimus dorsi, deltoid (posterior);
– pectoralis major from flexed position- triceps (long head).
Medial Rotation – subscapularis, pectoralis major, deltoid (anterior), – latissimus dorsi, teres major;
Lateral Rotation – infraspinatus, teres minor, deltoid (posterior).
Key Muscles that act across the Shoulder Joint.
Dermatomes
Case
• 9 Years old boy fell on his shoulder while playing on the monkey bars, he is experiencing pain, and inability to
Lift his left arm this is his X-ray
What’s your diagnosis?
Clavicle Fractures
Fracture Clavicle
Glossary
• Pectoral: Worn on the chest or breast• Girdle: Something that encircles like a belt
References
• www.medicalstudents.com• www.google.com• www.dcfirst.com/
surface_arm_muscle_anatomy_posters.html• http://
etl2.library.musc.edu/surface_anatomy/core/structures/003.html
• http://www.shoulderdoc.co.uk/article.asp?section=902
• http://depts.washington.edu/msatlas/105.html